#include <stdio.h>

int main(){
    int lvalue = 0;
    char opt = 0;
    int rvalue = 0;
    printf("请输入表达式:");
    scanf("%d%c%d", &lvalue, &opt, &rvalue);
    switch(opt){
        case '+':
            printf("%d\n", lvalue + rvalue);
            break;
        case '-':
            printf("%d\n", lvalue - rvalue);
            break;
        case '*':
            printf("%d\n", lvalue * rvalue);
            break;
        case '/':
            printf("%.2lf\n", (double)lvalue / (double)rvalue);
            break;
        default:
            printf("目前只支持 + - * / 运算\n");
            break;
    }
    return 0;
}
